641332020181 has 2 divisors, whose sum is σ = 641332020182. Its totient is φ = 641332020180.

The previous prime is 641332020137. The next prime is 641332020187. The reversal of 641332020181 is 181020233146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 634875897681 + 6456122500 = 796791^2 + 80350^2 .

It is a cyclic number.

It is not a de Polignac number, because 641332020181 - 2¹⁷ = 641331889109 is a prime.

It is a super-2 number, since 2×641332020181² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641332020187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320666010090 + 320666010091.

It is an arithmetic number, because the mean of its divisors is an integer number (320666010091).

Almost surely, 2^641332020181 is an apocalyptic number.

It is an amenable number.

641332020181 is a deficient number, since it is larger than the sum of its proper divisors (1).

641332020181 is an equidigital number, since it uses as much as digits as its factorization.

641332020181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 31.

The spelling of 641332020181 in words is "six hundred forty-one billion, three hundred thirty-two million, twenty thousand, one hundred eighty-one".